Rivet squeezer and the like



Aug. 21, 1945. P. F. RossMANN 2,383,082

RIVET SQUEEZER AND THE LIKE Filed June 30, 1942 2 Sheets-Sheet 1F'IC5-4.

ATTORNEY Aug. 2l, 1945. P. F. RossMANN RIVET SQUEEZER AND THE LIKE FiledJune 30, 1942 2 Sheets-Sheet 2 F'IG.6.

INVENTOR.

, PlsToN TRAVEL.

F`| G. IO.

ATTO RN E Y Patented Aug. 21, 1945 l UNITED STATES PATENT OFFICE RIVETSQUEEZER AND THE LIKE Peter F. Rossmann, Snyder, N. Y.

Application June 30, 1942, Serial No. 449,191

(ci. '1s-42) l 4 claims The present invention relates generally tomachines or devices of the type embodying relativelyreciprocatingmembers for applying pressure to Work positioned betweensaid members, more particularly to a rivet squeezer, but equally usefulfor punching, Dressing, forging and similar operations.

An object of the invention is to provide a rivet squeezer lor the likeconstructed and arranged applied to the work, thereby greatly increasingits flexibility in use and allowing of manual or direct hand operation.

A further object is to provide a rivet squeezer or the like capable ofenabling ank accurate control of the extent of travel of its relativelymovable or pressure applying member by the operator, in particular tostop the pressure application at any point of the working stroke of thedevice to existing requirements and operating condi- 1ons.

These and further objects of the invention will be in part discussed andinpart become apparent from the following detailed description of twopractical embodiments thereof taken with reference to the accompanyingdrawings forming part of this specication and wherein:

Figure 1 is a longitudinal cross-sectional view of a rivet squeezer, inthe normal or,nonuse position. embodying the principles of theinvention; Figure 2 is a section taken on line 2-2 of Figure 1; Figure 3is a section taken on line 3-3 of Figure 1; Figure 4 is a partial `topview of Figure 1; Figure 5 is a fragmental view of Figure 1 showing theposition at an intermediate point during the working stroke; Figure 6 isa longitudinal cross sectional view of a rivetvsqueezer similar toFigure 1 and/embodying a modiiication of the invention; Figure 7 is `aview similar to Figure 6 being in part in elevation and showing theposition at an intermediate point of the operating stroke; Figure 8 is asection taken on line 8-8 of Figure 6; Figure 9 is a section taken online 9 9 of Figure 6; and Figure 10 is a plot showing .the Workingpressure obtained during the operating stroke with a device according tothe invention compared with known rivet squeezers at present incommercial use.

Like reference characters identify like parts throughout the differentviews of the drawings. Referring to the embodiment of the 'invention`shown in Figures 1 to 4, the numeral 10 indicates a cylindrical housingof my improved rivet squeezerhaving an integral` end wall II at itsfront and being provided with a screwed-on or otherwise' secured coveror cap I2 at its rear,

said cap havingy an integral cylindrical extension or sleeve I3 oflesser diameter than and coaxial with the housing I0.

The movable unit of the squeezer comprises a hollow shaft I4 carrying ananvil or rivet set I5 at its front end and serving to support aplurality--four beingshown in the drawingsof disc-shaped pistons I6preferably equally spaced from each other and supported by the innercas- `ing wall in such a manner that the entire assembly comprising.said shaft and pistons is free to move axially. In the exampleillustrated, the pistons I6 having an inner diameter to afford `an easyslip-lit over the shaft I4are secured Yto the latter by means ofring-shaped spacers I1 and a nut I8 engaging the threaded en d of therearwall of the housing Ill by means of outer spacerA rings 24 similarto the spacers I1 and clamped between the outer edges of the discs 23 bythe cap I2 gripping the rearward-most disc 23 with the forward-mostspacer engaging the f rqpt wall II of the housing I0. The inner edgesofthe discs are fitted with suitable packings 25 retained by packing rings28 which are connected, by rivets 2l or otherwise secured to the discsto provide an airtight, slidable connection with the spacer rings I1 ofthe movable unit. Similarly, the outer edges of the pistons I6 arefitted with packings 28 retained by packing rings 30 which are connectedby rivets 32 or otherwise securedto the pistons to provide an air-tightsliding engagement with the outer stationary spacer rings 24. There arethus provided a plurality of high and static pressure chambers to theright and left of each The static pressure cham-bers S are constantlyconnected with the outside atmosphere through chambers H passing throughthe wall of said shaft and the spacing rings I1. As more clearly shown lin Figures 2 and 3, the spacing rings I1 and 24 are provided withannular grooves 34' and 33', respectively, registering with ancommunicating with the adjacent portholes whereby the ingress and egressof compressed air or other medium is insured in any relative position ofsaid rings with respect to the shaft I4 and housing I0, respectively.

There is further provided in Figure 1 a cooperating anvil or rivet set35 disposed opposite to the anvil I5 and adjustably mounted in the freeend of a removable yoke screwed on or other- Wise detachably secured toa threaded extension sleeve 31 of the housing I0, said `sleeve acting asa bearing for the anvil I5. Any other type of pressure applicator may beprovided depending on the use and purpose for which the squeezer isdesigned as will be readily understood.

In order to move the entire piston assembly comprising parts I4, I5, I1,I8 and to apply pressure to the work such as a; rivet placed between theanvil I5 and the cooperating anvil or rivet set, 35, there is providedan adjustable valve structure for admitting compressed air, liquid or anequivalent medium into the high pressure chambers H, said valve beingdesigned in such a manner as to synchronize the movement of the valveadjusting element controlled by the operator with the advance or travelof the pistons so as lto enable an accurate control of the speed andmovement of anvil I5 and in turn of the degree and period of pressureapplication to ,the work being operated on within the operating range orworking stroke of the squeezer.

presently. Valve member 45 is normally urged into its rearward-most orzero position by any suitable means consisting in the example shown,

, of a coiled compression spring 48 encircling the In order to normallymaintain the squeezer in the zero or starting position shown in Figure1, there is provided in .the example shown a coiled compression spring38 arranged within shaft I4, the rear end of said spring engaging a plug40 screwed into the end oi' the rear shaft portion 20 to form an air orliquid-tight closure and the front end of said spring bearing againstthe rear K end of a cylindrical plug 4I'placed inside the shaft I4 andhaving its front end engaging the inside of anvil I5. Plug 4I whichsnugly'flts within the shaft I4 is retained against rotation by means ofa pin 42 mounted in press-fit ensagement within a bore .through theextension 31 of the housing. Shaft I4 is further provided with a slot 43engaged by pin 42 to enable axial movement of the shaft within a givenrange or stroke for which .the device is designed. The plug4I isfurthermore of sufiicientlength to act as a seal for and preventcompressed air within shaft I5 from entering the forward-most staticpressure chamber.

The control ^nd valve mechanism comprises a cylindrical, suitablyknurled or uted hand grip 44 rotatably mounted upon the extension sleeveI3 of .the housing I 5 and a cylindrical valve member 45 in snug fittingand rotating engagement with the inside oi' sleeve I3. Said valve memberhas an inner diameter somewhat larger than the diameter of the adjacentshaft portion 2li and is provided with an inwardly directed annularflange or rim 45 engaging the outer lsurface of shaft portion 20 andserving as a valve element cooperating with the 'inlet portholes 41through said shaft in the manner to be described rearward-most spacingring I1 with one end engaging the rearward-most separating disc 23 andwith its other end bearing against a shoulder of the member`45.

Valve member 45 is connected with the hand grip'44 through a pin or setscrew 5I) having an intermediate portion arranged to move within anoblique guide slot 5 I in the sleeve I3 (see Figvure 4), wherebyrotation of hand grip 44 will result in an axial forward movement of thevalve member 45. A flexible tube 52 'from a supply tank of compressedair or the like (not shown) is screwedinto the rear end of the sleeveI3, the arrow A in the drawings indicating the direction of entrance ofthe compressed air or other medium.

The function and operation of the rivet squeezer aforedescribed is asfollows: In the zero or rest position shown in Figure 1, both the staticand high pressure chambers S and H are connected to the outsideatmosphere directhr through the pontholes 33 on Ithe one hand andthrough portholes 34 by way of the inside of shaft I4, valve portholes41 and exhaust portholes 53 on the other hand, respectively. In thisposition, the compressed air supply as indicated by the arrow A isblocked by the valve element 46 which closely engages the outer surfaceof rear shaft portion 20. If now the hand grip 44 is rotated in theclockwise direction, .the valve member 45 will advance axially in theforward direction against the action of the spring 48 due to .the pin I5sliding within the guide slot 5I in the manner described. As a result,the valve element 4B will at first cover the portholes 41 therebyshutting of! .the high pressure chambers H from the outside air. Furtheradvance of the valve by continued rotation of the hand grip 44 willresult in the uncovering of the valve ports 41 as shown in Figure 5 andadmission of compressed air or other medium. Accordingly therefore thecompressed air will enter the inside of shaft I4 and pass throughingress portholes 34 into the high pressure chambers H, the path of theair being indicated by the dotted arrows in Figure 5. All the pistons I6will thus be simultaneously moved in the forward direction, resulting ina corresponding advance of the anvil or rivet set I5 and application ofpressure to the work such as a rivet placed therebetween and thecooperating anvil 35. The position of anvil I5 at the end of the workingstroke has been indicated in dashed lines in Figure l.

The'employment of a plurality of simultaneously operated pistons intandem arrangement as shown has the eii'ect of a correspondinglyincreased total pressure applied by the anvil I5 and l results in ahighly compact rivet squeezer of considerably reduced size and weightsuitable for hand operation even for comparatively large size rivets orworking pressures.

The initial movement of the piston I5 as a result of the rotation of thehand grip 44 to a certain extent in the manner described, in its turnwill entail an axial forward movement oi' the shaft I4, 20 which forms arigid unit together with the pistons, whereby after a certain advance ofthe pistons determined by the initial extent of rotation of the handgrip. the valve will be returned to its relative initialposition.wherein the 'valve element 45 will again register with lcoiled spring 38of Figure 1.

the speed of travel during the complete power stroke, the length of thestroke and degree of pressure application may be controlled andindividually adjusted to suit existing requirements and conditions. l A

Upon release of the-hand grip either at the end of the operating strokeor at any intermediate point thereof, the valve will be returned to itszero or starting position by the spring 48 as shown in Figure 1, wherebythe inside of the shaft will be connected with the outside atmosphere,allowing the compressed air in the pressure chambers ,HH to escapethrough portholes 34, shaft I5, valve portholes 41 and exhaust portholes53. At the same time, the spring 38 will return the entire movable unitto its rearwardmost or starting position as shown in Figure 1.

From the foregoing itwill be understood that the tandem arrangement of aplurality of pistons simultaneously operated by a`suitab1e compressedmedium may be used in connection with e this manner, by-a follow upcontrol of this type,

any other known type of valve and control device and vthat the.synchronized or follow-up control of the piston travel or pressureapplication is not limited to the use of more than one piston but may beemployed in combination with any type of piston Without departing fromthe scope and spirit of the invention.

Referring to Figures 6 to 9, there is shown a modified power squeezerdiffering from the con-k struction of Figure 1 by the; elimination ofthe return spring 38 and provision 4of means to return to and maintainthe movable unit in its zero position by pneumatic pressure. The housingIll, separating discs 23, the movable unit comprising pistons IS andshaft I4 as well as the operating parts M, 45, and 50 of the valvestructure are substantially similar to those according to Figures 1 to 5with the exception that the outer portholes 33 are omitted and one ormore pistons, in the example shown the rearward-most piston IS', arearranged for'operation by air -pressure in-either direction. Accordinglytherefore the chambers Hs and SH on the opposite sides of piston I6' are.utilized both as high and static .pressure chambers to cause piston I6'to act simultaneousl'y withv the remaining pistons during' rearward-mostor zero position. In other words, piston I6' serves bbthas an operatingpiston together with the remaining pistons I6 during the forward travelin the same manner as in the case of Figure 1 and is utilizedadditionally as a means to return and urge the movable unit into itsz'ero position; that is, taking the place of the For the aforementionedpurpose, there is provided in the embodiment according to Figures 6 td amodified valve structure designed in such aj-manner that normally, i.e., in the zero position ofthe squeezer shown in Figure 6, the highpressure chambers H aredisconnected from the com-l pressed airsupplywith the exception of charnber Hs to the left of the return piston I6insuch a manner that the movable unit will be urged to and maintained inthe rearward-most or zero position. At the same time, the staticpressure chambers Sand the chamber SH to the right of the return pistonI6' are connected with the outside atmosphere. Upon rotation of the handgrip or other control element, the valve will assume a position so as toadmit "compressed air into the high pressure chambers H in a mannersimilar to that according to Figures 1 to 5, while at the same time therelationship between chambers Hs and SH on both sides of the returnpiston I6 will be reversed, i. e., chamber Hs will become a staticpressure chamber connected to the outside atmosphere similar tothe.chambers S, while chamber Sn will become a high pressure chamberconnected to the compressed vair supply similar to the chambers H. Thevalve is advantageously so constructed thatat rst the change from staticto high pressure and vice versa in the chambers SH and Hs will beeiected, whereupon the compressed air will ne admitted to all the highpressurechambers for initiating the power strokevand effecting theadvance oi the anvil or other pressure applicator.

Upon release of the hand grip at a point within or at the end of theworking stroke, the. valve to 9 by means of a modified valve structurecom-` prising a rst tube 55 snugly fitting and slidable within the shaftI4, said tube containing two separate longitudianl chambers s and h suchas. in the embodiment shown, by the provision of la further tube 56 oflesser diameter brazed to or otherwise secured to the inside of tube 55as shown more clearly at 51 in Figures 8 and 9. Chamber h lispermanently under high pressure by direct connectionto the high pressureintake valve chamber Vn, and tubular chamber s having its opposite endshermetically closed by means of plugs 60 and VG'I is connected to theoutside or static pressure through. the exhaustv portholes 62 at therear end of tubes 55 and 56 communil cating with the static pressurevalve chamber Vs which in turn communicates with the outside atmospherethrough the exhaust portholes 53.

` The high and static pressure valve chambers Vn and V. are separated bythe inner flange or .rim 63 of valve member 45 rigidly secured in anairtight manner such as by shrinking or the like to the projecting rightLend of valve tube 55. As

- a result, rotation of the hand grip Il will cause groove in themembers I1 and 55 andcooperating portholes through the members 55, Il,I1 and 55, 55, Il and Il, respectively, Ais such, that in the zeroposition as shown in Figure 6, all the chambers S as well as chamber SHare at static pressure being connected t chamber s, while chamber Hs isconnected to the high pressure chamber h. thereby urging the entiremovable unit into its rearward-most or zero position.

If the hand grip 44 is now rotated in a clockwise direction to a certainextent as shown in Figure 7, at rst the relationship between chambers Hsand Sn is reversed, i. e., chamber Hs is tion with Figure 1. If the handgrip is released,

the relative movement of the valve tubes 55 and 56 with respect to theshaft Il will be reversed by the return spring I8 urging the valve backinto its zero or rearward-most position. During this return movement thechambers H are temporarily connected with the chamber s thereby allowingthe air inithe high pressure chambers to escapeto the outside, whereuponat the end of the valve return movement chamber Hs will be connected tochamber h and chamber SH will be connected to chamber s, resulting in areturn of the entire movable unit to its rearwardmost or zero positionin the manner understood from the foregoing.

Due to the use of piston I6 as an operating element both during theforward travel and for eifecting the return of the pistons to the zeroposition, the chamber enclosed by the two rearward-most separating discs23 and 23 has to be increased accordingly depending on the extent of thetravel or operating stroke, and the piston I6 as well as disc 23' arefitted with suitable packings on either side thereof by reason of thefact that air pressure is applied to b'othsides of these members.

An advantage of a squeezer according to the invention, in addition tothe accurate and gradual control of the travel or operating stroke inthe manner described, is the fact that the desired pressure isdirectlyapplied from the pistons to the pressure-applying member or anvil by theuse of a suitable number of pistons in tandem substantially without anyintermediate linkage or like power transmission mechanisms as used intherprior art devices in order to obtain a desired working pressure. Inaddition, the pressure applied by the squeezer according to theinvention is substantially constant throughout the entire working strokecompared with the gradual pressure application from an initial low valueto the final pressure in case of devices employing linkage or othertransmitting mechanism between the piston and anvil or other pressureapplicator, as illustrated at a and b in Figure 10, respectively,representing the plots of the working pressure during the piston strokeobtained by the invention and with the known constructions,respectively.

While I have shown and described a few desix'able embodiments oi theinvention, it isun- '/'Vderstood that this disclosure is for the purposeof illustration and that various changes in shape, proportion andarrangement of parts as well as the substitution of equivalent elementsfor those herein shown and described may be made without departing fromthe spirit and scope of the invention as dened in the appended claims.

I claim:

1. In a rivet squeezer, a housing forming a cylinder having a pluralityof chambers, a plurality of pistons each movable within one of saidchambers, a hollow piston rod extending into all the chambers andIprojecting from both ends of said cylinder, said piston rod having inletport means connecting the inside thereof with said chambers on one sideof said pistons, a rivet set at one of the projecting ends of said rod,a yoke carrying a cooperating riveting tooland secured to said housing,control means for admitting compressed air or fluid through said rod tosaid chambers, said control means comprising an adjustable valve membercarried by an extension of said housing and cooperating with an inletopening of and arranged at the opposite vprojecting end of said rod, andmeans to resiliently urge both said piston rod and said valve Imember toa predetermined starting position, whereby to normally interrupt thesupply of compressed air or fluid to said chambers and to synchronize ina continua1 follow-up action the advance and return of said pistons withthe adjusting movement of said valve member.

2. In a rivet squeezer, a housing forming a cylinder, at least onepiston movable within said cylinder, a hollow piston rod projecting fromboth ends of said cylinder, said rod having inlet port means connectingthe inside thereof with said cylinder on one side of said piston, arivet set at one of the projecting ends of said rod, a yoke carrying acooperating riveting tool and secured to said housing, control means foradmitting compressed air or uid through said rod to said cylinder, saidcontrol means comprising an adjustable valve member carrier by anextension of said housing and cooperating with an inlet opening of andarranged at the opposite end of said rod, and means to resiliently urgeboth said piston rod and said valve member to a predetermined startingposition, whereby to normally interrupt the supply of compressed air orfluid to said cylinder and to synchronize in a continual follow-upaction the advance and return of said piston with the adjusting movementof said valve member.

3. In a rivet squeezer, a housing forming a cylinder, at least onepiston movable within said cylinder, a hollow piston rod projecting fromboth ends of said cylinder, said rod having inlet port means connectingthe inside thereof with said vcylinder on one side of said piston, arivet set at at the opposite projecting end 0f said rod, and.

means to resiliently urge both said piston rod and said valve member -toa predetermined starting position, whereby to normally interrupt thesupply of compressed air or fluid to said cylinder and to synchronize ina continual follow-up action the advance and vreturn of said piston withthe ad-

